Base/Neutral Extractables Mixture (20 µg/mL in Methanol) . U-625-MA ( 1 x 1 mL ) Phenols Mixture (20 µg/mL in Methanol) . U-PHM-604 ( 1 x 1 mL ) Base/Neutrals Surrogate Standard Mixture (1000 µg/mL in Methylene chloride) . U-ISM-280N ( 1